AM_Helmutwinklerite Formula: Pb Zn2 As2 (O10 H2) Name: Helmutwinklerite Unit cell: 5.606 5.61 7.617 70.19 69.91 69.18 , V=203.77 Space group: P-1 (2)

Krause W , Belendorff K , Bernhardt H J , McCammon C A , Effenberger H , Mikenda W , European Journal of Mineralogy , 10 (1998) p.179-206, Crystal chemistry of the tsumcorite-group minerals. New data on ferrilotharmeyerite,, tsumcorite, thometzekite, mounanaite, helmutwinklerite, and a redefinition of gartrellite